Use of polarization analysis in the understanding of resonant magnetic x-ray scattering at the L2,3 edges of rare earths

The concomitant development of new x-ray sources, new dedicated instruments and of the theory of resonant X-ray magnetic scattering (RXMS) has opened a permanently developing range of new experiments, where one takes advantage of the coupling of the x-ray beam polarization with the magnetic moments. In rare earths, RXMS allows one to study separately the contributions of the 4f and 5d electrons to the magnetism. We present a preliminary study on samarium and dysprosium and show that qualitative considerations on the energy dependencies of magnetic intensities (peak intensities at magnetic Bragg positions) allows clear identification of the two contributions to the resonance. The energy lineshapes of the resonances are discussed in terms of the introduction of collective effects (band structure of the 5d level) into the single-ion model of the resonance.